De acordo com o código-fonte ZFS , o número máximo é definido como 1024. Posso confirmar que 1024 ACLs podem ser definidas em um arquivo no ZFS no Solaris. Pode haver um limite inferior na implementação do ZFS ou setfacl no FreeBSD
# cat maxacl
#!/bin/ksh
touch file
i=1
while true; do
for u in $(getent passwd | nawk -F: '{print $1}'); do
chmod A+user:$u:read_data:allow file || break 2
printf "%d %s\n" $i $u
i=$((i+1))
done
ls -v file | head
ls -v file | wc -l
done
# ls -v file | head
-rw-r--r--+ 1 root root 0 déc 6 13:05 file
0:user:utku3:read_data:allow
1:user:utku2:read_data:allow
2:user:utku1:read_data:allow
3:user:utku0:read_data:allow
4:user:utwww:read_data:allow
5:user:jlliagre:read_data:allow
6:user:nobody4:read_data:allow
7:user:noaccess:read_data:allow
8:user:nobody:read_data:allow
# ls -v file | tail
1017:user:root:read_data:allow
1018:owner@:execute:deny
1019:owner@:read_data/write_data/append_data/write_xattr/write_attributes
/write_acl/write_owner:allow
1020:group@:write_data/append_data/execute:deny
1021:group@:read_data:allow
1022:everyone@:write_data/append_data/write_xattr/execute/write_attributes
/write_acl/write_owner:deny
1023:everyone@:read_data/read_xattr/read_attributes/read_acl/synchronize
:allow